Synchronized touch input recognition

Abstract

Embodiments are disclosed for a touch-based device and methods for operation thereof. One embodiment provides a touch-based device having a display with a plurality of pixels and a touch input sensor overlying the display. The touch input sensor has a plurality of touch regions, each of which overlie an associated set of the pixels. The touch-based device further comprises a display controller configured to update the pixels according to a schema during which pixels are updated during update periods. The touch-based device yet further comprises a touch controller configured to recognize selectively applied touch inputs at the plurality of touch regions. The touch controller and the display controller are synchronized such that, for a given touch region, touch input recognition is modified while the display controller is updating the set of pixels associated with that touch region.

The invention claimed is: 
     
       1. A touch-based device, comprising:
 a display having a plurality of pixels; 
 a touch input sensor overlying the display and comprising a plurality of touch regions overlying an associated set of the pixels; 
 a display controller configured to update the pixels according to a schema during which pixels are updated during update periods; and 
 a touch controller configured to recognize selectively applied touch inputs at the plurality of touch regions, 
 wherein the touch controller and the display controller are synchronized wherein for a given touch region, touch input recognition is modified while the display controller is updating the set of pixels associated with that touch region, 
 wherein the display controller and the touch controller are further synchronized based on an exchange of state information, the state information comprising at least a refresh rate of the display controller, 
 wherein a measurement voltage applied to the touch input sensor is increased based on an increase in the refresh rate of the display controller. 
 
     
     
       2. The touch-based device of  claim 1 , wherein the touch input recognition is modified by disabling touch input recognition for the given touch region while the display controller is updating the set of pixels associated with that touch region. 
     
     
       3. The touch-based device of  claim 1 , wherein the touch input recognition is modified by using, for the given touch region, a different filter for touch input recognition while the display controller is updating the set of pixels associated with the region. 
     
     
       4. The touch-based device of  claim 1 , wherein the touch input recognition is modified by applying, for the given touch region, a different measurement voltage to the touch input sensor. 
     
     
       5. The touch-based device of  claim 1 , wherein the touch controller and the display controller are synchronized wherein, for a given touch region, touch input recognition is selectively enabled and disabled based on how recently the associated set of pixels have been updated. 
     
     
       6. The touch-based device of  claim 1 , wherein the update periods are separated by blanking periods during which none of the pixels are updated, and wherein the display controller and touch controller are synchronized to control recognition of touch inputs based on whether the touch-based device is in an update period or a blanking period. 
     
     
       7. The touch-based device of  claim 6 , wherein the pixels are arranged in a plurality of rows with the schema including a row update period for each row followed by a horizontal blanking period, the display controller and the touch controller being synchronized wherein, for a given row of pixels, touch input recognition for touch regions associated with the row of pixels is modified by disabling touch input recognition during the row update period and enabling touch input recognition during the horizontal blanking period following the row update period. 
     
     
       8. The touch-based device of  claim 6 , wherein the blanking periods comprise horizontal blanking periods and vertical blanking periods, and wherein the display controller and touch controller are synchronized to disable touch input recognition for one or more of the touch regions during the update periods and enable touch recognition for those touch regions during the horizontal and vertical blanking periods. 
     
     
       9. A method of operating a touch-based device including a touch input sensor overlying a display having a plurality of pixels, the touch input sensor comprising a plurality of touch regions, each of which overlie an associated set of the pixels of the display, the method comprising:
 updating the pixels, wherein such updating is controlled by a display controller; 
 recognizing, with a touch controller, selectively applied touch inputs at the plurality of touch regions; 
 synchronizing the display controller and the touch controller wherein, for a given touch region, the recognizing of selectively applied touch inputs comprises modifying touch input recognition while the display controller is updating the pixels associated with that touch region, the synchronizing being performed based on exchanging state information between the display controller and the touch controller, the state information comprising at least a refresh rate of the display controller; and 
 increasing a measurement voltage applied to the touch input sensor based on an increase in the refresh rate of the display controller. 
 
     
     
       10. The method of  claim 9 , wherein the modifying of touch input recognition comprises disabling touch input recognition for the given touch region while the display controller is updating the set of pixels associated with that touch region. 
     
     
       11. The method of  claim 9 , wherein the modifying of touch input recognition comprises, for the given touch region, using a different filter for touch input recognition while the display controller is updating the set of pixels associated with the region. 
     
     
       12. The method of  claim 9 , wherein the modifying of touch input recognition comprises, for the given touch region, applying a different measurement voltage to the touch input sensor. 
     
     
       13. The method of  claim 9 , further comprising selectively enabling and disabling touch input recognition for a given touch region based on how recently the associated set of pixels have been updated. 
     
     
       14. The method of  claim 9 , wherein the pixels are updated by the display controller according to a schema comprising update periods during which the pixels are updated and blanking periods during which none of the pixels are updated, the method further comprising synchronizing the display controller and the touch controller so that touch input recognition is controlled differently in update periods than in blanking periods. 
     
     
       15. The method of  claim 14 , wherein the pixels are arranged in a plurality of rows with the schema comprising a row update period for each row followed by a horizontal blanking period, the display controller and the touch controller being synchronized wherein, for a given row of pixels, touch input recognition for touch regions associated with the row of pixels is modified by disabling touch input recognition during the row update period and enabling touch input recognition during the horizontal blanking period following the row update period. 
     
     
       16. The method of  claim 14 , wherein the blanking periods comprise horizontal blanking periods and vertical blanking periods, and wherein the display controller and touch controller are synchronized to disable touch input recognition for one or more of the touch regions during the update periods and enable touch recognition for those touch regions during the horizontal and vertical blanking periods. 
     
     
       17. A method of operating a touch-based device comprising a touch input sensor overlying a display having a plurality of pixels, the touch input sensor having a plurality of touch regions, each of which overlie an associated set of the pixels of the display, the method comprising:
 updating the pixels, wherein such updating is controlled by a display controller according to a repeatedly executed sequential schema, during which pixels are updated sequentially row by row during row update periods that are followed by horizontal blanking periods, with a vertical blanking period following update of a last row of pixels; 
 passing state information from the display controller to a touch controller configured to recognize selectively applied touch inputs at the plurality of touch regions, such state information specifying a current location of updating the sequential schema and a refresh rate of the display controller; 
 controlling, with the touch controller, touch input recognition based on the state information; and 
 increasing a measurement voltage applied to the touch input sensor based on an increase in the refresh rate of the display controller. 
 
     
     
       18. The method of  claim 17 , wherein the controlling of touch input recognition based on the state information comprises disabling touch input recognition for one of the touch regions when the state information indicates that a pixel in the touch region is being updated. 
     
     
       19. The method of  claim 17 , wherein the controlling of touch input recognition based on the state information comprises disabling touch input recognition other than when the state information indicates that a horizontal blanking period or a vertical blanking period is occurring. 
     
     
       20. The method of  claim 17 , wherein the controlling of touch input recognition based on the state information includes, when the state information indicates that a pixel in one of the touch regions is being updated, performing at least one of (i) using a different filter for touch recognition in the touch region; and (ii) applying a different measurement voltage to the touch input sensor for the touch region. 
     
     
       21. The touch-based device of  claim 1 , wherein the touch input recognition is performed for a touch region according to a default approach when the set of pixels associated with the touch region are not being updated. 
     
     
       22. The touch-based device of  claim 1 , wherein a measurement voltage applied to the touch input sensor is decreased based on at least one of:
 a decrease in a display refresh rate of the display controller; and 
 during a blanking period corresponding to a period when the pixels are not being updated. 
 
     
     
       23. The touch-based device of  claim 1 , wherein the touch controller is operable to update a scanning frequency of the touch input sensor to substantially match a change in the refresh rate of the display controller.